This invention relates to a new antibiotic substance, designated Cp-57,820. Said new antibiotic substance has been identified as a new member of the nargenicin family of antibiotics, and it has been named nargenicin C.sub.1. Nargenicin C.sub.1 has been obtained from fermentations of a new microorganism which was isolated from a soil sample collected in Georgia, U.S.A., and which has been designated culture N467-32. Culture N467-32 is considered as a member of the genus Nocardia, and it is designated as Nocardia sp.
The following nargenicins are already known:
______________________________________ ##STR1## (I) Nargenicin R.sup.1 R.sup.2 R.sup.3 R.sup.4 ______________________________________ A.sub.1 OCH.sub.3 H H OH 18-deoxy A.sub.1 OCH.sub.3 H H H B.sub.1 OH OCH.sub.3 OCH.sub.3 OH B.sub.2 OH OCH.sub.3 OH H B.sub.3 OH H OCH.sub.3 OH ______________________________________
See further, U.S. Pat. No. 4,148,883 and Celmer et al., Journal of the American Chemical Society, 102, 4203 (1980); Whaley et al., 21st Interscience Conference on Antimicrobial Agents and Chemotherapy, Chicago, IL, Abstract No. 187, Nov. 4-6, 1981; U.S. Pat. No. 4,224,314 and Tone et al., 20th Interscience Conference on Antimicrobial Agents and Chemotherapy, New Orleans, LA, Abstract No. 62, Sept. 22-24, 1980.